Expander tools



pril 3, 1956 C. LAVALy 1R 2,740,456

EXPANDER TOOLS Filed Oct. 5 1953 4 Sheets-Sheet l f4. f@ :E: @s HOV ib lE /o gw M (D) 35 4" f7, y 3 am; f

|I" I UH. /0 i I J-Ml jle f- 46 E I a@ E EE 23R mi E I 1| 6 I 1 45 E 45gO O 1 E 50 50-4 I 48 CLAUDE A1/,4L JR /NVEA/rof? E HUEBNER, BEEHLER,

WORREL a HERZ/6 ,e1/7 Arm/wey: H6" By 6 M April 3, 1956 c. LAVAL, JR2,740,456

EXPANDER TooLs Filed Oct. 5, 1953 4 Sheets-Sheet 2 ,2s/e f .I l' t C ma@o @a www April 3, 1956 c. LAVAL, JR 2,740,456

EXPANDER TOOLS Filed OCT.. 5, 1955 4 Sheets-Shee Z5 CLAUDE AVA/ JR.

/NVENTOR HuE/VER, EEHLE/Q,

WOR/PEL a HERZ/G ATTORNEYS April 3, 1956 C, LAVAL, JR 2,740,456

EXPANDER TOOLS Filed OCT.. 5, 1953 4 Sheets-Sheet 4 38 CLAUDE LAVA/ JR.

HUEBNER, @Eem/5R, wom/5L a HERZ/6 A77' ORNE VS` www Unite The presentinvention relates to expander tools and more particularly to such a toolfor forcibly .distending .Qblcts by which it is receivable, such ascollapsed or improperly fonned well casings, pipes, tubes, conduits,objects having boreholes and the like.

While the tool has a wide range of applications 'where its poweredvexpansion is of use, it was initially produced vfor therepair ofcollapsed well casings and is conveniently illustrated in connectionwith such operations. Theshifting of subterranean formations, imbalanceof external and internal pressures, and the action of well tools .andoperating equipment frequently deform well casings to such an extentthat these wells are inoperable until the deformations are rectified. Afrequently occurring problem is the collapsing of the casings so thaty.their minimum transverse dimensions are inadequate to receive or to,house operable drilling equipment, pumping apparatus or repair tools.

Although many tools have been devised for the purpose, it is currentlythe general practice to redrill the portion of the well containing thecollapsed casing or successively to drop a pointed weight into thecollapsed portion with the hope that the resultant blind hammeringalleviates more than it aggravates the pinched condition. Beth practicesare of such questionable effect that valuable wells which have beendamaged arefrequently abandoned without trying either. The redrilling istime consuming, expensive, damaging to excessive amounts of the casingand frequently results in a departure from the initial bore and theforming of ,a bifurcated well, neither forks of which may be effectivelyemployed nor conveniently isolated from the other. The weight droppingpractice usually fails to utilize the momentum of the falling weightadvantageously, 4,outward penetration of the casing is common, and muchdenting andY dimpling results. In the event either operation issuccessful, it is then necessary to insert a reinforcing sleeve at theposition of difficulty .and to ,secure it in a dependable manner.Neither the burred .condition of a drilled casing nor the dimpled anddented state of a weight-hammered casing is conducive to convenient andproper fit-ting of such sleeves.

Of the other tools intended for the purpose, most are even lesseffective than the practices described .and thus have not generally beenaccepted; many Vrequire .time consuming lowering and retrieving by meansof a tubing string utilized for power supply or control purposes, suchstring requiring the assembly ,and subsequent disassembly of numerouslengths of drill pipe; and most provide inadequate power to expandcollapsed casing, or such ineicient application of available power, asto be ineffective except in most opportune situations. Further, eventhough casing faults frequently occur at great depths and at positionsof extreme uid pressures, none have recognized nor been adapted to theseadditional difticulties and .several are rendered inoperable thereby.For example, the inaccuracies of the droppi-ng are considerablyincreased and its impacting power immeasur- :ably decreased .by itsfalling through liquid `for substantial distances before exerting itsstriking force. The usual confining of well liquids in casings causesthe liquids to retard rapid movement of such weights yeven more, thanEnright otherwise occur.

An object of the lpresent invention is to provide an improved expandertool successfully operable forcibly to distend collapsed, improperlyformed, and/or incompletely shaped well casings, pipes, tubes, conduits,vbore- :holes :and the like.

Another object is to provide an expander tool that can .hespeedily andeasily lowered vinto a well or -the like to, an operating depth andretrieved therefrom.

.Another object is to provide -an `expanderztool that isgaccurately anddependably remotely controlled.

Another object is to provide a tool-of the 'character described that-can be suspended ona cable for ease :and :speed of lowering and raisingand .that is fully controllable vwhileso suspended.

Another object is to provide Aa well casing tool which `is capable-tofoperating etiiciently at ,extreme we'l'l depths. More .specifically itis an object to design the tool :so that it can withstand highenvironmental pressures as en- -countered in deep wells withoutsignificantly impairing .operational accuracy or eiciency.

Another object is `.to provide a well tcasing tool consisting of a ,selfsucient unit including a housing,a working memberexternally oftheyhousing,.and'equipment yfor .operatingthe working .member containedinthe housing.

Another object is to provide .a well casing tool'of a .constructionwhich insures its lowering tinto, fand'from, Well casing without dangerof wedging or stickingY therein.

Another object is to provide a well casing tool which is capable ofexerting large lateral pressures against 'the sides of a `collapsed wellcasing without jarring or hammering the casing and incurring the hazardsand `damages .incidentthereto These, and other objects of this invention`will become more fully apparent upon reference to the followingvdescription and accompanying draw-ings, in which:

Fig. 1 is a side elevation of an expander tool embody-V ing theprinciples of this invention shown supported in .a well -casingillustrated in vertical section.

Fig. 2 is a view similar to Fig. 1, ybut showing a portion of theexpander tool brokenv away permitting observation of the interiorthereof.

Fig. 3 is a fragmentary diagrammatic view of Ythe tool and a hydraulicactuating system therefor. l

Fig. 4 is a somewhat enlarged fragmentary view similar to that of Fig. 2but showing a portion `of the tool in section on a plane ninety degreesremoved from Ythat of Fig. ,2.

Fig. 5 is a fragmentary side elevation of the portion of the tool shownin Fig. 4, certain element-s there'o'f'being sectioned for illustrativeconvenience.

Fig. 6 is an enlarged fragmentary section taken online 6 6 of Fig. 1.

Fig. 7 is a View similar to Fig. 6, showing elements of the tool in asuccessive stage of operation.`

Fig. 8 is an enlarged fragmentary section taken on line. 8-8 of Fig. 4showing internal details of a hydraulic control valve utilized in thetool.

Fig. 9 is an enlarged section taken on line 9-9- of Fig. 5.

Fig. 1'0 is a transverse section of the tool taken at the positionindicated at 1li-10 in Fig. 6.

Fig. 1l is a transverse section taken atthe position indicated at 11-11in Fig. 6.

Fig. 1.2 is an end elevation of theexpander .tool viewed from theworking end thereof.

Fig. '13 is a transverse section taken at the position indicated at13--13 of Fig. 4 showing a reservoir for operating iluid.

Fig. 14 is a section of the reservoir shown in Fig. 13, viewed from asectioning plane ninety degrees removed from the sectioning plane ofFig. 13, as shown by line 14-14 in Fig. 4, and with elements of thereservoir in a successive stage of operation.

Fig. 15 is a transverse section taken at the position indicated by theline 15-1S in Fig. 4.

Fig. 16 is a longitudinal section of a pump used in the hydraulic systemof this invention, taken on line 16-16 of Fig. 4.Y

Fig. 17 is a section of the pump of Fig. 16 taken on line 17-17 of Fig.5.

Fig. 18 is a section taken on line 15-18 of Fig. 5

Referring more particularly to the drawings, the numeral l@ in Fig. ldenotes a portion of a well casing containing therein a fluid 12 such asoil or water. Supported by a cable 14 is an elongated torpedo-shapedhousing generally indicated by the numeral 16. The

housing 16 is constructed of a heavy gauge steel or the like havingadequate strength to resist damage thereto as well as to the equipmentcontained therein as a result of fluid pressure on the outer wallthereof or abrasion with objects of an operating environment such as awell casing. While it is to be understood that the tool may be employedin any desired attitude, it is conveniently described in the pendantposition shown in the drawings. The housing 16 is divided into an uppersection 18 and a lower section 2t). The upper section l consists of anelongated hollow cover portion 22 having a streamlined upper snap-on orloosely tting closure member 24. The cover 22 is further threadablyattached at its lower end in uid tight engagement to a boss 26 on thelower section 29. The closure member 24 is provided with an opening 2Sfor receiving the cable 14 and other control wires subsequently to bedescribed. The closure member is preferably not fixedly attached to thehousing, as by threads, in order that it may be easily removed in anemergency so that access may be had to the supporting bracket describedbelow, by heavy grappling tools or the like.

The threaded boss 26 is also used for supporting on its top surface anelongated iiat plate member 36 which in turn mounts the various elementswithin the upper section 18 of the housing subsequently described. Theplate member 30 is secured at its top against movement by a transversebar 31 extending laterally from the plate and abutting against the cover22 when in position, thus providing a three-point contact for the platewithin cylindrical cover 22. A U-shaped supporting bracket 34 for thepurpose of attaching the cable 14 or other grappling hook thereto issecured to a plate 32 threadedly received in the upper end of housingcover 22.

A hydraulic system is supported on plate member 3i) and consists of anupper reservoir 36 near the upper end of member 30, an electric motor 3Smounted beneath the upper reservoir, and a speed reducing transmissionsystem 40 connected between the output of the motor 38 and the input ofa luid pump 42. Beneath the fluid pump 42 and also supported on plateFail is an electrically operated fluid control Valve 44. The operationand association of the various elements in the hydraulic system is bestunderstood by reference to Fig. 3, and will subsequently be referred toin detail.

Referring in particular to Figs. l, 2, 6 and 7, attention is devoted tothe lower section 2? of housing i6. This portion of the housing consistsof three main parts, an upper steel casting 45 within which is formed acylinder 46 and which is threadably secured to a lower casting 47 influid tight engagement. A plurality of segmental arms or jaws 48 arepivotally attached to the lower end of casting 47, as at 50, and dependdownwardly when relaxed cooperatively to form anose on the housing.

Mounted for reciprocaticn within the cylinder 46 is a d ram or piston 52connected at its underside, as viewed, toa rod 54. Motion is transmittedfrom rod 54 to the ngers 48 through a lower head or piston 58 andconnecting rod 56, its associated head 57 and a set of links, thedetails of which will subsequently be described.

The general operation of the invention thus far described is as follows.The housing 16 is lowered within the Well casing 10 by means of thecable 14 to a desired depth of operation. By means of electrical controlwires to be described, the motor 3S and valve 44 are energized whereuponlluid pressure is built up in the hydraulic system. This pressure istransmitted from the upper seotion 18 of the housing throughY anyappropriate passage in the lower section 20 of the housing and intocylinder 46. This pressure acts to depress the piston 52 whereuponconnecting rods 54 and 56 are moved downwardly thus transmitting motionto the fingers or arms 48. to move them laterally outwardly against theinner wall o f the casing. When the casing has been properlystraightened, the supply of electrical energy is interrupted therebyde-energizing motor 38 and valve 44 whereupon the ram S2 is elevated andthe fingers 4S are collapsed.

Referring to Figs. 3, 4 and 5, a more specific description is given ofthe construction and operation of the hydraulic system. Motor 38receives its electrical energy from a pair of wires 7d connected theretoand which k extend along with cable 14 through opening 28 to the surfaceof the well. While two wires are normally utilized, it will be apparentthat even a single wire will suftice with the circuit being completed toground; Although not shown, a suitable source of voltage is usuallyavailable or provided at the top of the well for connection to wires 7G.The output shaft of motor 38 is connected to an intermediate shaft 72having a universal drive joint at each end thereof. The latter connectsto a speed reducing transmission box 40, the specic details of which arenot important to this invention although represented in Fig. 4 asconsisting of a worm gear 74 and associated spur gear 76. The obviouspurpose of the transmission is to give the motor 33 a mechanicaladvantage over the pump 42. While a wide range of vara7 tions in motorpower, pump capacity, and reduction ratio of the transmission can beemployed, it is appropriate to observe that an embodiment of the subjectinvention utilizing a loth horsepower motor and a transmission having areduction ratio of the order of approximately 700-1 has provedexcellently suited to the purpose and has developed a lateral thrust bythe spreading lingers 48 of approximately one hundred tons, whichexperience has shown is tar greater than normally required in correctingcollapsed Well casings.

The spur gear 76 is mounted concentrically on a shaft 77 rotatablymounted in the transmission and having eccentric journals at oppositeends thereof. A lever 78 is rotatably mounted on each of the eccentricjournals of the shaft and extended therefrom in substantially parallelrelation. Each of the levers has an extended end pivotally connected toa bell crank 80 pivotally mounted on the channel support member 30, asat 81. The bell cranks provide arms extended toward the pump 42. Thepump provides an operating handle 82 extended toward the transmission 4dwhich actuates the pump when piv otally reciprocated. A toggle link 83interconnects the extended ends of the arms of the bell cranks with theextended end of the operating handle of the pump. It will be seen thatupon rotation of the shaft 77, the lever 78 oscillates the bell cranks89 to actuate the handle 82 by means of the links 83.

The pump 42 comprises a cylinder portion 84, as seen in Fig. 3 and Figs.16 to 18, for slidably and reciprocally receiving a piston 86, thelatter being coupled to the handle 82. Thus pivoting action of handle 82reciprocates the piston 86 in cylinder 84. The pump is provided withinlet and outlet ports 9i) and 92, respectively, the former beingconnected to a second reservoir 94 which forms an 5 integral portion ofpump 42. Pump 42 has a pressure relief valve 91, shown in Fig. 18, andcheck-valves 9.3 and 9S, shown in Figs. 16 and i3, which are for,theusual purposes.

As previously noted, the electrically operated control valve 44 ismounted beneath the pump 42. This valve hasa chamber 96 formed thereinwhich is connected by means of a ud conduit 93 to the outlet port.-92;Inaddition, the valve provides a bore 99 therein adjacent to thechamber. Chamber 96 has an outlet port or uid passage 100 opening intothe bore which may be opened or closed depending upon the position of avalve member 162 mounted for sliding movement in bore 99 against theaction of a spring 101. As shown in Fig. 3, the valve member 102 isprovided with a reduced diametrical portion 103 intermediate its endswhich, if aligned with port 100 and a port or fluid passage 104 at theopposite side of the bore, permits fluid communication between saidports. Port104 is connected'to the second reservoir 94 by means of iluidconduit 106. The chamber 96 of the control valve 44 is also connectedfor uid flow to the cylinder 46 by means of conduit 108. Electricalcontrol is provided for the valve 44 by means of a solenoid 110 which ismounted on a plate 111 extending from the valve, as best seen in Fig. 8,and which receives its energization from line 70. Solenoid 110 isconventional in construction, having an armature which bears against onearm of a bell crank lever 112 pivotally mounted so that the other armabuts against the outer end of valve member 102. When solenoid 110 is ina de-energized condition, the valve member 102 is in the open-portposition-,shown in Fig. 3, being urged into this position by a spring113. When the solenoid is energized, the bell crank pivots clockwiseagainst the action of spring 113 thereby permitting valve 102 to slideoutwardly under the nuence` of spring 101. it will be` noted thatreservoir 36 is connected to reservoir 94 by means of conduit 114 andc0- operates therewith to insure a proper supply of uid in the hydraulicsystem. The two reservoirs can be incorporated into one but theconstruction shown has proved convenient and suited to the utilizationof conventionally available materials in the restricted spaces of thehousing. An inflatable bag or envelope 1-16 is provided within the upperreservo-ir 36 and isnormally in a substantially deflated condition, asshown. Wheniluid is drawn from this reservoir, bag 116 distends, asshown, in Fig. 14 to permit the drawing of iluid from the reservoirwithout operating against a vacuum. A free air pocket would have thesame capabilities but should be isolated from the hydraulic iluid toavoid entering the system and imparting an undesirableresilienceto-theoperation incident to the compresssibility of air. AHuid conduit 11S is provided with a valve and is connected to reservoir94 for the purpose of filling this reservoir with the hydraulic lluid tobe used. A similar conduit and valve, indicated at 120, are provided forlilling reservoir 36.

Referring to Figs. 6, 7, and l to l2, the specific construction of thelower section 20 of the housing is readily described. The upper casting45 of this lower section is provided with a vertically extending uidconduit passage 200 which is attached at one end to the conduit 108 andopens .at the other end into the cylinder 46. The'piston 52appropriately employs a plurality of cup leathers 202 mounted on a bodymember 204 in the well-known manner. The connecting rod 54 is rigidlyattached at its upper end to the piston S2 and extends downwardly forsliding movement within bore 20S formed in the lower casting 47. Aspring 210 is optionally provided between the lower end of ram 52 andthe upper end of casting47 to urge ram 52 toward its uppermost position.The connecting rod 50 abuts against the head 53 of lower connecting rod56 and is loosely connected thereto by means ofja pair of ear members,as212, extending upwardly-from diametrically opposite sides of the headS and having elongated openings therethrough into-which pins213 ex-.tending laterally from the rod are received. This .arrangement is suchthat during the downward stroke. of the ram 52 connection between rod 54andrheadSS isfby abutment thereby permitting a limitedamountofswivellingto occur in the rod 56 as well as eliminating cornpressional strain onthe pins 213 or ears 212. During the upward lstroke however, the rods5.4 and 56 are connected by the ear-and-pin arrangement to retract thelower connecting rod. It will be understood however, that since directcoupling of the rods only occurs in tension i. e. during the upwardstroke, severe forces vtending to shear the pin are'avoided.

Toaidin retracting the piston 58, a compressionspring 214 is optionallyprovided in the bore 208 below the piston. A ball check valve 215 isprovided in the side of casing portion 206 and leading into bore 208`for a purpose to be subsequently described.

The specific construction of the arms 48 is best shown in Figs. 6, 7,and 1'0 through 12. Each of the arms constitutes a longitudinal segmentof a generally acutely paraboloidal extension of the housing 16 whichwhen nested, as shown in Fig. 1, presents a streamline lower end for thehousing 16. The lower end of each of the arms has an inwardly curvednose portion 216 which has its outer surface roughened as bytheprovision of transverse, casev hardened ribs 217 for the purpose Iogripping the sides of the well casing or other work piece. Each arm ispivoted to-the casting47, `as at 50, and optionally has a light spring218 attached on the inner side thereof to a point on casting 4'7inwardly of its re,- spective pivot. Likewise, each arm has an arcuatetransverse recess 219 in the nose portion 216 thereofvwhich, when thearms are collapsed, asin Fig. 6n1ates withpan adjacent recess in anadjacent arm to form a continuous annular groove. A light spring 220 isplaced in this groove and together with springs 218 comprise means forpreventing arms 48 from moving out of their-collapsed position in ahaphazard manner while transporting the well casing tool above ground,wheninserting and lower ing it into the well and when raising it fromthe well.

Each arm 4S is also provided with an open socket222 best seen in Figs. 7and 10 at a point immediately above the nose portion thereof. Eachsocket 222 is constructed to releasably receive the ball shaped end of alink 224,. Although the links may be actually pivotally. or swivellyconnected to their respective arms, the releasable associ ationdescribed is an assembly convenience and adequate for the exertion ofoutward thrust on the arms, no retractive force or tensioning ofthelinks being required. This is more clearly ascertainable from Fig. 7where it will be evident that sockets 222 provide a wide arc of verticalmovement as well as a limited amount of swivel movement for link 224.

Because the well tool of this invention is frequently used in a verticalposition such that they arms48 hang downwardly from the body ofthehousingit willbe apparent that when the expanding pressure isreleased, from the arms, they tend, due-to gravity and external environFmental pressure, to collapse from a positionA such as shown in Fig. 7 tothe position shown in Fig. 6. This collapsing is also aided by thesprings 218 and 220-alf though the more prominent purpose of thesesprings` is to hold the arms in a collapsed condition whentransportf ingthe tool. Thus a removable association between each link 224 and itsrespective arm 48 has been found satis* factory and as notedaboveolierscertain advantagfsv over a xed connection.

Each link 224 is also provided with a ball 226 at its inner end which isreceivable in a socket 228 in a base 230 formed on the rod 56. kThesockets retain the ball end of the links therein :but permit limitedswivelling movement thereof and in particularl a relatively widevertical arc of movement, again asseenbest in Fig.l 7. The upper ledgeof each socket 228 and the lower ledge of each socket 222 cooperate inestablishing a limiting means for spreading movement ol the arms 48, aswill be apparent.

lt should be understood that housing 16 is made as completely fluidtight as possible throughout. However, it has been found desirable tofill the upper section l with a dielectric fluid 233, such astransformer oil, for the purpose of resisting external pressuresexisting at extreme well depths as well as providing a pressureexternally of the hydraulic system which tends to minimize leakagethereof. The presence of the fluid also excludes oxygen and thusobviates the possibility of a lire within the housing. Pressureequalization is obtained between the inside and outside of the housingby providing a flexible diaphragm 232 in a small area of the cover 22.As the pressure increases or decreases on the outside of the housing,this diaphragm exes to equalize the pressures and thus prevents unduestrain on the housing walls and compensates for any comprcssibility ofthe iluid incident to gas dissolved therein.

Operation ln operation the tool is lowered in the faulty well casing tothe desired depth of operation or positioned in any other desired workpiece, whereupon motor 38 and solenoid 11i) are energized by the closingof a switch, as 234, located at the surface of the well therebysupplying voltage to line 7i). Rotation of *te motor 33 causes theoperating handle 52 to move in and out thereby reciprocating the piston86. Hydraulic luid is drawn from the reservoirs 36 and 94 through inletport 9i? into cylinder 8e and thereupon. out the port 92 and intochamber 96 through the conduit 93. ince the solenoid il@ has beenenergized the valve member i152 is in the port-closed positionpreventing 'the passage of fluid from port li to port ldd. Therefore,uid must flow out of chamber 96 through conduit 14.*3 and into thecylinder 46 through passage Zilli. When sullicient pressure is built upin the hydraulic system, piston 52 is moved downwardly and thereby,through connecting rods 54 and 56, the arms 48 are expanded or spreadoutwardly. As lluid is pumped from the reservoir 36, the partially gaslled bag 116 expands to replace such removed iluid. rl`his not onlymakes possible the fluid removal from the reservoir in the closed systembut creates a reduced pressure in the reservoir which tends to draw thepumped tluid back into the reservoir when the pump is deactivated.

When it is desired to collapse the arms d8, switch 234 is opened therebydez-energizing the motor 3S and solenoid 110. Since the motor 3d isstatic, pump d2 will cease to increase pressure in the system. When thesolenoid 110 is de-energized, the valve lil?. moves into the port-openposition establishing fluid communication between chamber 96 and theconduit 166. Thus, as piston 52 moves upwardly under the urging ofspring 2li), it forces uid through conduit 168 into chamber 96, throughthe now open valve HB2, into conduit 1%6, back to reservoir 94, andthrough conduit lid to reservoir 36. Fluid cannot flow from chamber 95bacl; toward pump 42 in conduit @S duc to the closed condition of valvesEl and 93. Upward movement of the piston 52 causes both connecting rods5d and 56 likewise to move upwardly thereby removing the outwardpressure exerted on. the arms through links 224. This permits the arms4.8 to move inwardly to a collapsed position as described above wherebythe tool can be removed from the well casing.

It is appropriate to observe, that the principal retractive effects arethose of the gravitational tendencies of the arms 4S to return to nestedrelation, shown in Fig. l, and the automatic lay-passing of the pump 42by the control valve d4 so that hydraulic fluid h1 the cylinder candischarge back to the reservoirs incident to the existence of greaterpressure inthe cylinder i6 than exists in the reservoirs from which thefluid has been pumped. Further, the jarring of the arms '33 against thecasing 1i) 8 Y as the tool is pendantly supported therein tends toretract the arms. Of secondary retractive effect are the springs 220 and218 which possess utility but which are optionally employed. The spring210 is of course of aid in retracting the piston 52.

lt should be noted that although 0-rings 241 are shown about the rod 56and head 56, they act to filter the uid rather than prevent its flow. Toprevent this leaked-in fluid from collecting under ram :'52 and creatingan upward pressure during the downward stroke, pressure relief valve23.5 has been provided. Because of the uni-directional characteristic ofthe cup leathers 262, this fluid also occasionally leaks by the cupleathers 202 and into the space above piston 52. When the tool is beinglowered into or removed from a well, the hydraulic system is in a staticcondition and therefore there is no downward fluid pressure in theconduit 168. Thus the well uid leaking into the lower section of thehousing and by the cup-leather, as above described, tends to build up apressure in the hydraulic system and unless provision is made for itsrelease, eventually the pressure created on the top of the piston S2becomes large enough to depress it. It is believed to be clearlyapparent that it this were to happen the ngers 48 would expand therebylocking the tool at some undesirable position in the hole during thelowering or raising operation.

To prevent this action, a pressure relief diaphragm 246 is mounted in anextension 247 of the upper reservoir 36 which projects to the exteriorof the housing 16, as best shown in Fig. 5. When well fluid leaks intothe upper portion of cylinder 46 above the piston 52 and thereupon intothe hydraulic system through passage 28? it does not remain trapped inthis position but instead creates a pressure in reservoir 36 throughconduit 36S, chamber 96, open valve 102, conduit N6, reservoir 94, andconduit 114. This pressure acts to distend the diaphragm 246 so thatsuch pressure tending to expand the arms is relieved, and the danger ofinadvertent locking in the well is obviated.

Diaphragm 246 also has a conjoint effect with inflatable bag 116 offlexing inwardly during actuation of the hydraulic system` and thus aidsin preventing air pockets from forming therein, as discussed above, as aresult of gas dissolved in the hydraulic lluid.

Although the invention has been herein shown and described in what isconceived to be the most practical and preferred embodiment', it isrecognized that departures may be made therefrom within the scope of theinvention, which is not to be limited to the` details disclosed hereinbut is to be accorded the full scope of the claims so as to embrace anyand all equivalent devices and apparatus.

Having described my invention, what I claim as new and desire to secureby Letters Patent is:

l. An expander tool comprising an elongated housing, said housing havingupper and lower sections, said upper section being substantially hollow;a iluid communicating duct between said upper and lower sections; meansconnected to said lower section and being laterally expansible forengagement with a well casing; hydraulic pressure means supported insaid hollow upper section for actuating said expansible means andcomprising a lluid pump, a reservoir connected to said pump, and a valveconnected to said pump, reservoir and duct and having two positions ofoperation whereby in energized position fluid is permitted to fiow'onlyfrom said pump into said duct and in the de-energizcd position fluid ispermitted to dow only from said duct into said reservoir; and electricalmeans for energizing said pump and valve.

2. A well casing tool comprising an elongated fluidtight housing, saidhousing having a cylindrical chamber therein and a central bore axiallyextended from the chamber, a ram mounted for recprocation in saidchamber, a plurality of depending segmental arms pivotally attached tosaid housing and being laterally extendable therefrom, linkagesassociated with the arms, connecting ama-ane rod means extended throughthe bore between` said ram and each of said linkages for transmissionor? movement therebetween,` electrically controlled hydraulic means insaid housing, and a uid communicating duct connecting said chamber withsaid hydraulic means, said hydraulic means being adapted to establish allud pressure in said chamber for depressing said ram and extending saidarms.

3; A well casing tool comprising an elongated iluidtight housing, saidhousing being divided into removably connected upper and lower sections,means connected to said upper section for lowering said housing into ailud containing well casing, said lower section having interconnectedupper and lower portions, a cylindrical chamber formed in said upperportion and a central bore formed in said lower portion, a ramreciprocally mounted in said chamber and having a connecting rodextending therefrom into said bore, a plurality of segmented armspivotally dependingly attached to said lower portion and laterallyspreadable into engagement with the well casing, linkage meansassociated with each of said arms and with. a further connecting rodextending into said bore, said last mentioned connecting rod beingprovided with a headed member in abutting relationship with said firstmentioned connecting rod, electrically controlled hydraulic means insaid upper section, and a iluid communicating passage connecting saidchamber with said hydraulic means, said hydraulic means being adapted toestablish a iluid pressure above said ram in said chamber whereby tospread said arms by depression of said ram.

4. A well casing tool for repairing the interior of a Well casingcomprising an elongated fluid-tight housing, said housing having upperand lower sections; a plurality of segmental expanderV arms dependentlypivotally mounted on the lower section of said housing and adapted uponexpansion to engage the interior of a well casing; means ferloweringsaid housing into a iluid containing well casing; the lower sectionhaving a cylinder formed therein; a piston mounted for reciprocation insaid cylinder', means connecting the piston to said arms for controllingthe expansion thereof; a hydraulic system mounted within said uppersection including a fluid pump, a motor kfor driving said pump, areservoir having a supply of iluid therein, and an electrically operatedtluid control valve, said pump having inlet and outiet ports;` lluidconducting means connected between said outlet port and said valve,between said inlet port and said reservoir and between both saidcylinder and reservoir and said control valve; and electrical conductingmeans extendihle out of said housing and connected to said motor andcontrol valve for supplying power thereto whereby upon energization ofsaid motor and valve tluid is forced from the pump through the valve andinto the cylinder for depressing the ram and expanding the arms and uponde-energization of said motor and valve, fluid is forced from thecylinder through the valve and into the reservoir permitting elevationoftheram'and collapse of the arms.

5. A well casing tool comprising an elongated ilu'idtight housing, saidhousing being divided into upper and lower sections, said upper sectionbeing substantially hollow; means connected to said upper section forlowering said housing into a fluid containing well casing; said lowersection having interconnected upper and lower portions, a cylindricalchamber within said upper portion and a central bore formed in saidlower portion; aV piston reciprocally mounted in said chamber and havinga con= necting rod extending therefrom into said bore; a 'secondconnecting rod slidably mounted in the bore; a plurality of segmentedarms pivotally dependingly attached to said lower portion and laterallyspreadable. into engagement with the well casing; linkage meansassociated with each of said arms and with the second connecting rod;said second connecting rod being provided with a headedmemb'er inabutting relationship with said rst mentioned connecting rod; a iluidpressure establishing means supported in the upper section for spreadingsaid arms, said pressureV means including vva uid pump, a" fluidi-supplyreservoir connectedto said pump, and a iluidicontrolfvalve connected toea-chV of saidrpump,`A reservoir and chamber and constituting a by-passfor iluid flow byrsaitlgpump during the inoperative condition thereof;the'enpergization of said pump and valveI being synchronized and beingelectrically controlled remotely from saidshousing.A

6. In a remotely controlled tool, the combination.y of a housing,workpiece engaging means mounted: on vthe housing for movement betweenav workpieceengaging position and a retracted position, anhydraulicframgmount;n ed in the housinghaving controlled connectionf tothe workpiece engaging means, a reservoir for hydraulicdiuid, anelectrically energized pump connected-tothe reservoir., electricallycontrolled r'neansvhaving iluid connectionto thepump, to the ram, andtothe reservoir, said electrically controlled means .having anenergizedconditionin which fluid passage therethroughrfrom thepumprtothe ram is provided and a de-energized condition inuwhioh fluidpassage from the ram` tothe. reservoir in.,.byp,ass relation to the pumpis provided., and en .electrical system connected to the pump andvto theelectrically. controlled means adapted concurrently to energize andtodesenergize the same.

7. in a remotely controlled tool, the combination= of a housing,workpiece engaging means mounted onl the housing for movement between aworkpiece. engaging position and a retracted position, meansresiliently`urging the workpiece engaging means into retracted rpositiorganhydraulic ram mounted in thehousing having controlled connectionto theworkpiece engaging means, a reservoir for hydraulic iluid,.anelectrically energized pump. con.- nected to the reservoir, electricallycontrolled ,means,having fluid connection to the pump, to the ram;andlothe eservoir, said" electrically controlled meansy havingV anenergized condition in whichlluid passagetherethrough from the pump tothe ram isprovided and a, de-energized condition in which ,lluidpassagefrom theramto thereservoir in by-pass. relation to the pumpisprovided, andran electrical system connected to thef pump and to theelectrically controlled means adapted for connection to,.a source ofelectrical energy remote from thehousing. and disconnection therefromwhereby thepurnp andv tht-electrically controlled means are concurrentlyenergized and de-energized.

8; An expander tool comprisingan elongated housing having acylindricalcha-mber formed therein and acentra'l bore axially extendedfrom the chamber, a Vpiston reciprocally mounted inthe chamber andhaving apiston rod extended therefrom intothe bore, a.plurality offsegfmental expander arms `pivotally dependently attached. to the housingandv laterally spreadable therefrom, a con nectingj rod extended intothe bore having an. endfin abutting relation with` the pistonrod,linkage means interconnectingfthe arms andthe connecting rod, andelcc-Vtrically controlledjhydraulic.means mountedinthe housing having iluidconnectionfwith the chamber, the hydraulic means beingadapted toestablish a. tluidA pressure in the chamber endwardly of the pistonwhereby the pistonis movedand-through the piston-rod, connect ing rod,and linkage means-the arms are laterally spread.

9. A remotely controlled expander. tool comprising`-ta housing providinga chamber, a pistonslidably fitted to the chamber and reciprocaltherein, means. connectedto the housing laterallyexpandable `therefromto engagea workpieceto be. expanded, actuating meansfconnectingcthelaterally expandable means to the piston,A a `source of hydraulic fluidapump having an. inletconnected.- tothe source of. hydraulic lluid and anoutlettconnected torthe chamber operable1 upon actuation to force fluidinto the chamber to extend theipiston and therebyy to actuatethelaterally expandablemeans, anielectrical lvsystem: connected to the pumpfor actuation thereof uponenergization. of the system, switch,. meansfor energizinggand de-energizin'g the electrical"` system, and tluidcontrol/means. interv4 connecting the chamber and the source ofhydraulic uid responsive to energization of the electrical system forblocking lluid ilow between the chamber and the source of hydraulictluid and responsive to de-energization of the electrical system forpermitting such liuid ilow.

10. A well casing tool comprising an elongated housing adapted to belowered into a well casing, laterally expansible means connected to thehousing for engagement with the well casing, a ram in the housingconnected to the expansible means for actuation thereof, a liuidreservoir in the housing, a pump having a fluid inlet connected to thereservoir and a uid outlet connected to the ram, means permittingunidirectional lluid ow from the reservoir through the pump to the lluidoutlet, a valve mounted in the housing having iluid connection to theram and to the reservoir and having a first position blocking fluidpassage between the reservoir and the ram and a second positionpermitting liuid passage between the reservoir and the ram, resilientmeans urging the valve into said second position, and an electricalsystem connected to the pump and to the valve having an energizedcondition adapted to actuate the pump and to urge the valve into saidrst position and a Cle-energized condition adapted to de-energize thepump and to tlc-energize the valve for movement of the valve by theresilient means into said second position.

1l. A remotely controlled expander tool comprising a housing providing achamber, a piston slidably reciprocal in the chamber, means laterallyexpandable from the housing to engage a workpiece to be expanded, meansconnecting the laterally expandable means to the piston, a source ofhydraulic liuid, a pump having an outlet connected to the chamber and aninlet connected to the source of hydraulic fluid, a two-way lluidcontrol valve interconnecting the chamber and the source of hydraulicuid having an open position permitting lluid flow from the chamber tothe source of hydraulic fluid and a closed position blocking such lluidllow therethrough, resilient means urging the valve into open position,electromagnetic means operable upon energization to urge the valve intoclosed position and upon de-energization to free the valve for closingby the resilient means, and electrical control means for synchronouslyenergizing and deenergizing the pump and the electromagnetic means.

l2. A well casing tool comprising an elongated uidtight housingproviding a cylindrical chamber therein; a piston reciprocally mountedin the chamber; means connected to the housing laterally expandable toengage the interior of a well casing; means for elevationallypositioning the housing in a lluid containing well casing; meansconnecting the piston to the laterally expandable means for controllingthe expansion thereof; an hydraulic system mounted in the housingincluding a iluid reservoir, and an electrically driven lluid pumphaving an inlet connected to the reservoir and an outlet and beingadapted when energized to cause uid passage therethrough from the inletto the outlet; an electrically operated iluid control valve having acommon uid connection to the outlet of the pump and to the chamber and aseparate uid connection to the reservoir, the control Valve including amember positionable to permit fluid communication between the common andseparate duid connections when the Valve is :le-energized and to blocksuch fluid communication when the valve is energized; and an electricalsystem for operating the pump and the control valve including a switchremote from the housing having a closed position for concurrentlyenergizing the pump and the control valve and an open position forconcurrently energizing the pump and the control valve.

13. A well casing tool comprising an elongated uidtight housingproviding a cylindrical chamber therein, a piston reciprocally mountedin the chamber; means connected to the housing expandable laterally ofthe housing to engage the interior of a well casing; means forcontrollably positioning the housing in a uid containing Well casing;means connecting the piston to the laterally eX'- pandable means forcontrolling the expansion thereof; an hydraulic system mounted in thehousing including a lluid reservoir, and a uid pump providing an inlethaving fluid connection to the reservoir and an outlet; a uid checkvalve in the liuid connection between the reservoir and the inlet of thepump adapted to preclude fluid llow from the outlet to the reservoirthrough the pump; an electrically operated iluid control valve providinga bore having uid connection to the reservoir and providing a uidchamber having fluid connection to the outlet of the pump and to thecylindrical chamber in the housing and having a port opening into thebore from the liuid chamber, a valve piston slidably mounted in the borefor vmovement between a position permitting fluid passage through theport between the iluid chamber and the uid connection from the bore tothe reservoir and a position blocking such fluid passage and a springurging the piston into open position; and an electrical system foroperating the pump and the control valve including a switch remote fromthe housing having a closed position for energizing'the pump and thecontrol valve to move the piston 'thereof` into blocking position andthe remote switch having an open n position for de-energizing the pumpand control valve to release the piston for movement by the valve springinto open position.

14. An expander tool comprising an elongated housing having acylindrical chamber therein and a central bore concentrically extendedendwardly from the chamber, a piston reciprocally mounted in thechamber, a piston rod connected to the piston and extended therefrominto the bore, laterally expandable workpiece engaging means connectedexternally to the housing, a connecting rod extended into the bore inabutting relation with the piston rod, means interconnecting thelaterally expandable means and the connecting rod for controlledexpansion and collapse of the expandable means in response to movementof the connecting rod, means yieldably urging the expandable means intocollapsed position, a fluid reservoir, a pump having an outlet connectedto the chamber and an inlet connected to the reservoir, a lluid controlvalve interconnecting the chamber and the reservoir having an openposition permitting fluid flow from the chamber to the reservoir and aclosed position blocking fluid llow therethrough, said valve beingresiliently urged into open position, electromagnetic means operableupon c nergization to urge the valve into closed position, andelectrical control means for correspondingly energizing andde-energizing the pump and the electromagnetic means.

l5. In a remotely controlled expander tool for boreholes and the like,the combination of a substantially fluid tight housing having oppositeends, means connected to the housing for positioning the housing in aborehole, a plurality of segmented arms pivotally attached to an endportion of the housing and extended longitudinally of the housing, saidarms being laterally spreadable into engagement with the Walls of aborehole and retractable therefrom, an hydraulic ram mounted in thehousing having a controlling connection to the arms, a reservoir forhydraulic uid within the housing, an electrically energized pump withinthe housing connected to the reservoir, electrically controlled meanswithin the housing having fluid connection to the pump, to the ram, andthe reservoir, said electrically controlled means having an energizedcondition in which fluid passage therethrough from the pump to the ramis provided and a fle-energized condition in which fluid passage fromthe ram to the reservoir in by-pass relation to the pump is provided,and an electrical system connected to the pump and to the electricallycontrolled means adapted concurrently to energize and to deenergize thesame by connection and dis-connection to a source of electrical energyremote from the housing.

(References on following page) References Cited in the le of this patentUNITED STATES PATENTS Ferren June 2, 1874 Stewart Jan. 20, 1914 GouldFeb. 19, 1924 Bierce Oct. 4, 1927 Steiner Feb. 18, 1930 Langstaff July1, 1930 Wagner June 26, 1934 10 14 Burt Sept. 3, 1935 Carey Jan. 12,1937 Danner Aug. 17, 1943 Fisher Apr. 4, 1944 Merten Sept. 26, 1944Kirby Mar. 27, 1951 Audemar May 20, 1952 Koch June 30, 1953

